CN210773884U - Steel bar detection device in concrete - Google Patents
Steel bar detection device in concrete Download PDFInfo
- Publication number
- CN210773884U CN210773884U CN201922035488.2U CN201922035488U CN210773884U CN 210773884 U CN210773884 U CN 210773884U CN 201922035488 U CN201922035488 U CN 201922035488U CN 210773884 U CN210773884 U CN 210773884U
- Authority
- CN
- China
- Prior art keywords
- concrete
- capacitance
- steel bar
- detection
- electrode plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000004567 concrete Substances 0.000 title claims abstract description 41
- 238000001514 detection method Methods 0.000 title claims abstract description 33
- 229910000831 Steel Inorganic materials 0.000 title description 67
- 239000010959 steel Substances 0.000 title description 67
- 238000012545 processing Methods 0.000 claims abstract description 28
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 10
- 238000012360 testing method Methods 0.000 claims abstract description 9
- 238000007405 data analysis Methods 0.000 claims abstract description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 14
- 229910052802 copper Inorganic materials 0.000 claims description 14
- 239000010949 copper Substances 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims description 7
- 239000004926 polymethyl methacrylate Substances 0.000 claims description 7
- 230000007797 corrosion Effects 0.000 abstract description 25
- 238000005260 corrosion Methods 0.000 abstract description 25
- 239000011150 reinforced concrete Substances 0.000 abstract description 24
- 230000005686 electrostatic field Effects 0.000 abstract description 5
- 230000002787 reinforcement Effects 0.000 abstract description 4
- 239000011241 protective layer Substances 0.000 description 9
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 6
- 238000010276 construction Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000010410 layer Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 239000004033 plastic Substances 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000000840 electrochemical analysis Methods 0.000 description 2
- 230000005674 electromagnetic induction Effects 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- 238000003325 tomography Methods 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Images
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Abstract
Concrete in reinforcing bar detection device, provide a low-cost, high accuracy nondestructive test device based on electrostatic field electric capacity principle, implement the pertinence multinomial detection to the reinforcing bar in the concrete to acquire the accuracy and convenient testing result including reinforcing bar position, size and corrosion volume in the hope, realize improving the work efficiency that building engineering accepted and existing reinforced concrete structure's detection, reinforcement and appraisal. The detection device comprises a plate electrode, a direct current power supply and a data acquisition and processing device. The data acquisition and processing device comprises a capacitance meter, wherein the angular frequency of the capacitance meter is set to be 10 KHz; the display module is used for displaying a numerical value obtained after the capacitance sensor detects the numerical value; the operation module is used for manually and practically inputting specific engineering information to set parameters; the processing module is used for carrying out data analysis statistics on the value obtained by the capacitance meter and other related values; and the data connecting wire socket is used for connecting the electrode plate.
Description
Technical Field
The utility model relates to a be applied to and carry out nondestructive test's device to the reinforcing bar among the concrete structure belongs to the construction field.
Background
At present, in the construction of track traffic engineering such as commercial civil buildings, railways and highways, reinforced concrete structures are adopted for concrete construction. In order to ensure the construction quality and the subsequent long-term use safety, a plurality of special detection works need to be carried out on the steel bars in the concrete, which is the primary premise of ensuring the safety of the reinforced concrete structure.
According to the latest edition of the series of standards for construction quality acceptance of building engineering in China, the detection items of the steel bars in the concrete structure comprise whether the parameters of the position, the size and the like are consistent with those in a design drawing, whether the corrosion degree and the state are within the range of standard values and the like. In particular, the steel bar corrosion condition usually occurs in the concrete structure, and the evaluation of the service life and the bearing capacity of the building is difficult. Moreover, the corrosion of the steel bars can directly cause the collapse of the building, and the damage is extremely serious. When the damaged building is repaired, correspondingly accurate steel bar corrosion data also needs to be obtained. If early repair measures can be timely found and carried out in the early stage of corrosion of the steel bars, the cost is greatly reduced, and the economic loss is reduced.
In the prior art, for the detection of the steel bars in the concrete in the stage of infrastructure safety and construction acceptance, technologies such as an ultrasonic method, an electromagnetic induction method, a geological radar and tomography are mainly adopted. The electromagnetic induction method is a common detection method, can relatively accurately measure the position and the depth of the steel bar, but is easy to generate errors due to high requirements on environment and susceptibility to the influence of material components. The geological radar method is mainly used for layered detection of concrete and can also measure the position of a steel bar in the concrete, but the geological radar is relatively complex to operate and expensive in equipment. Tomography is also commonly used to evaluate concrete, but its application in practical engineering is limited due to expensive equipment and cumbersome operation and data processing.
In view of this, the present patent application is specifically proposed.
SUMMERY OF THE UTILITY MODEL
Concrete in reinforcing bar detection device, lie in solving the problem that above-mentioned prior art exists and provide a low cost, high accuracy nondestructive test device and method based on electrostatic field electric capacity principle, implement the pertinence multinomial detection to the reinforcing bar in the concrete to acquire the accuracy and convenient testing result including reinforcing bar position, size and corrosion volume in the hope, realize improving the work efficiency that building engineering accepted and existing reinforced concrete structure's detection, reinforcement and appraisal.
In order to achieve the design purpose, the device for detecting the steel bars in the concrete mainly comprises an electrode plate, a direct-current power supply and a data acquisition and processing device. Wherein,
the electrode plate comprises copper electrodes, polymethyl methacrylate and a water content testing device, wherein the two copper electrodes are placed at the same horizontal height and the same horizontal plane;
the data acquisition and processing device comprises a capacitance meter, wherein the angular frequency of the capacitance meter is set to be 10 KHz; the display module is used for displaying a numerical value obtained after the capacitance sensor detects the numerical value; the operation module is used for manually and practically inputting specific engineering information to set parameters; the processing module is used for carrying out data analysis statistics on the value obtained by the capacitance meter and other related values; and the data connecting wire socket is used for connecting the electrode plate.
On the basis of the application of the detection device, the application realizes a new detection method at the same time. Namely, the state of the steel bar is judged according to the capacitance value fluctuation condition and the capacitance value data, the calculation formula is as follows,
wherein C is the capacitance between two polar plates of the capacitance sensor, and takes Farad (F) as a unit; a is the (effective) area between the two plates, in square meters; epsilonrIs the relative dielectric constant of the material between the plates; ε is the absolute dielectric constant in vacuum (8.854X 10)-12Fm-1) (ii) a d is the spacing distance between the plates, in meters; the variation trend of the capacitance between the electrode plates shows that the position, the size and the corrosion amount of the steel bar in the concrete are different.
As mentioned above, the reinforcing bar detection device in this application concrete has the advantage be:
1. by adopting the electrostatic field capacitance principle, the position, the size, the corrosion amount and other data of the steel bar in the concrete can be detected quickly and accurately, a nondestructive detection means is realized, and the efficiency and the accuracy of project acceptance and detection identification work can be greatly improved.
2. The capacitive sensor is used for detecting and correcting data, the result is more accurate and convenient, the capacitive sensor is not influenced by material difference, and errors are effectively avoided.
Drawings
The present application will now be further described with reference to the following drawings.
FIG. 1 is a schematic view of a detection device according to the present application;
FIG. 2 is a schematic diagram of a data acquisition and processing device;
FIG. 3 is a schematic side cross-sectional view of the plate;
FIG. 4 is a schematic front cross-sectional view of the plate;
FIG. 5 is a graph showing analysis of the detected data;
FIG. 6 is a schematic view of detecting the position of a rebar;
FIG. 7 is a schematic view of the detection of the diameter of the steel bar;
FIG. 8 is a graph showing the relationship between the corrosion amount of steel bars and the capacitance.
In the above figures, there is, 1-display module; 2-polar plate connecting wire socket; 3-connecting a sliding trolley line; 4-an operation module; 5-an indicator light; 6-hooking; 7-computer connecting wire socket; 8-power charging wire socket; 9-switch button; 10-reinforcing steel bars; 11-an electrode plate; 12-connecting the polar plate with a data acquisition and processing device; 13-data acquisition and processing means; 14-concrete; 15-a copper electrode; 16-polymethyl methacrylate; 17-a plastic housing; 18-plastic filling.
Detailed Description
As shown in fig. 1 to 4, the device for detecting the steel bar in concrete is based on the electrostatic field capacitance principle, and mainly comprises an electrode plate 11, a direct current power supply, a data acquisition and processing device 13, and a connecting wire 12 for the electrode plate and the data acquisition and processing device.
Wherein, the electrode plate 11 comprises a copper electrode 15, polymethyl methacrylate 16 and a water content testing device.
The copper electrodes 15 (shown in fig. 4) are used for generating the exciting voltage and the induced voltage, the distance between the copper electrodes may be 0.5cm, the two copper electrodes 15 are placed at the same level and the same horizontal plane, and the size of the electrode plate 11 is 7.5cm × 4cm × 0.1 mm.
The packaging copper electrode 15 can adopt polymethyl methacrylate 16 to ensure that the electrode plate 11 is in an insulated state.
The plastic shell 17 further encapsulates the encapsulated polymethylmethacrylate 16, thereby effectively protecting the copper electrode 15. The polymethyl methacrylate 16 had dimensions of 8.5cm × 8.7cm × 2 mm.
The plastic shell 17 is a cubic structure, and the copper electrode 15 is tightly attached to the inner wall of one side of the shell 17 so as to facilitate detection.
The detection principle is to judge the state of the reinforcing steel bar according to the fluctuation condition of the capacitance value and the size of the capacitance value.
The capacitance value of a parallel capacitive sensor can be calculated by the following equation:
wherein C is the capacitance between two polar plates of the capacitance sensor, and takes Farad (F) as a unit;
a is the (effective) area between the two plates, in square meters;
εris the relative dielectric constant of the material between the plates;
ε is the absolute dielectric constant in vacuum (8.854X 10)-12Fm-1)；
d is the separation distance between the plates in meters.
Since the distance between the electrode plates 11 and the effective area of the electrode plates 11 are kept constant, the detection substance between the copper electrodes 15 changes, i.e., the dielectric constant (ε) between the copper electrode plates 15 changesr) The change occurs, so that the capacitance (C) between the electrode plates changes.
The difference in the position and size of the reinforcing steel bars in the concrete between the electrode plates 11 and the amount of corrosion of the reinforcing steel bars leads to the dielectric constant (epsilon) between the electrode platesr) Changes are made, and the state of the steel bars in the concrete is detected through the principle.
The dc power supply supplies a constant voltage of 1.0V to the electrode plate 11, so that the electrode plate 11 generates an excitation voltage.
The data acquisition and processing device 13 includes, as shown in fig. 2:
a capacitance meter for detecting capacitance values between the electrode plates 11, the angular frequency of which is set to 10 KHz;
the display module 1 is used for man-machine interaction operation after the detection, the display module 1 is connected with the capacitance meter to display the numerical value obtained after the detection of the capacitance sensor, and the numerical value can be displayed through numbers, curves and columns;
the operation module 4 is used for inputting some specific engineering information through manual actual operation, so that parameters can be set, display modes can be switched, and the brightness can be set;
the processing module is used for carrying out data analysis statistics on the value obtained by the capacitance meter and other related values;
the data connecting wire socket 2 is connected with the data acquisition and processing device 13 and the electrode plate 11;
the indicator lamp 5 is normally on to indicate that the equipment is normal, so that the normal work of the equipment is ensured;
the hook 6 is used for being convenient to carry during detection;
the computer connecting wire socket 7 is used for connecting with a computer so as to conveniently lead data into the computer for storage and further analysis and processing of the data;
and the power supply charging wire socket 10 is used for charging the data acquisition and processing device, ensuring normal work and providing voltage for the electrodes.
On the basis of the detection device, the following method for detecting the steel bars in the concrete is further realized.
The detection method is based on the electrostatic field capacitance principle and comprises the following implementation steps:
1) calibration
And the calibration refers to establishing a representation mapping with the state of the steel bar according to the capacitance value data. The calibration comprises the calibration of a capacitance value and the diameter of the steel bar, the calibration of the capacitance value and the thickness of the protective layer of the steel bar, the calibration of the capacitance value and the corrosion state of the steel bar and the like. In particular, the amount of the solvent to be used,
1.1 calibration of capacitance and diameter of steel bar
1.1.1, placing reinforcing steel bars with different diameters into the same batch of concrete with the same protective layer thickness, and curing the concrete for 28 days;
1.1.2 after the concrete is cured, putting the reinforced concrete to be tested into an oven to keep the water content of the reinforced concrete to be 0;
1.1.3 taking out the reinforced concrete to be detected with the water content of 0, scanning the electrode plate 11 along one side of the concrete to the other side at a constant speed by using a detection device, measuring capacitance values corresponding to different steel bar diameters, and establishing a one-to-one corresponding relation between the capacitance values and the steel bar diameters;
1.1.4, using a data acquisition and processing device to bring the capacitance value obtained in the previous step into a formula (1) to detect the diameter of the steel bar;
the formula (1) for representing the relation between the capacitance value and the diameter of the steel bar is as follows: c ═ aB2+bB+c。
1.2 calibration of capacitance value and thickness of steel bar protective layer
1.2.1 placing the steel bars with the same diameter into the same batch of concrete with different protective layer thicknesses, and curing the concrete for 28 days;
1.2.2 after the concrete is cured, putting the reinforced concrete to be tested into an oven to keep the water content of the reinforced concrete to be 0;
1.2.3 taking out the reinforced concrete to be measured, finishing the assembly of the sensor, scanning the polar plate along one side of a steel bar in the concrete to the other side at a constant speed, measuring capacitance values corresponding to the thicknesses of different steel bar protective layers, and establishing a one-to-one corresponding relation between the capacitance values and the thicknesses of the steel bar protective layers;
1.2.4 substituting the capacitance value obtained by the data acquisition and processing device into a formula (2) to detect the thickness of the steel bar protective layer; the formula (2) for representing the relation between the capacitance value and the thickness of the steel bar protection layer is as follows: c ═ eD2+fD+g。
1.3 calibration of capacitance and corrosion state of steel bar
1.3.1 placing the steel bars with the same diameter into the same batch of concrete with the same protective layer thickness, and curing the concrete for 28 days;
1.3.2 after the concrete is cured, carrying out reinforcement corrosion through an electrochemical test, and controlling the electrifying time to enable the reinforcement to generate corrosion amount of different degrees;
1.3.3 after the electrochemical test is finished, putting the reinforced concrete to be tested into an oven, and keeping the water content of the reinforced concrete to be 0.
1.3.4 taking out the reinforced concrete to be measured, finishing the assembly of the sensor, scanning the polar plate along one side of the steel bar in the concrete to the other side at a constant speed, and measuring capacitance values corresponding to different steel bar corrosion states;
1.3.5 taking the rusted steel bar out of the concrete, spraying an acidic rust removing solution on the surface of the rusted steel bar, and removing rust;
1.3.6 weighing the steel bars after derusting, comparing the weighed steel bars with the initial steel bar mass to obtain the steel bar corrosion amount, and establishing a one-to-one correspondence relationship between the capacitance value and the steel bar corrosion amount;
1.3.7, substituting the capacitance value and the steel bar corrosion amount obtained by the data acquisition and processing device into a formula (3) to carry out quantitative detection on the steel bar corrosion amount;
the formula (3) for representing the relationship between the capacitance and the corrosion state of the steel bar is as follows: c ═ K0*△M。
2) Actually measured data
2.1 connecting and starting the electrode plate and the data acquisition and processing device, wherein an indicator lamp in the data acquisition and processing device is always in a normally-on state, which indicates that the equipment is normal;
2.2 carry out actual detection to reinforced concrete structure
Placing the electrode plates on one side of the concrete, operating an operation module in the data acquisition and processing device, inputting necessary engineering information, scanning the electrode plates from one side of the concrete to the other side at a constant speed to obtain capacitance values of different positions, wherein the capacitance values between the electrode plates can be expressed as:
wherein C is the capacitance between the electrode plates, a is the length of the electrode plates, b is the width of the electrode plates, d is the spacing between the electrode plates, K0Coefficient of different kinds of reinforced concretexIs the relative dielectric constant between the electrode plates; under the condition that other parameters are not changed, the change of the relative dielectric constant between the electrode plates directly influences the change of the capacitance.
3) Data processing and analysis
3.1, carrying out scale marking on the test target along the moving direction of the electrode plate;
3.2 establishing a two-dimensional coordinate system, wherein the X axis is the scale of the moving direction of the electrode plate, and the Y axis is the capacitance value obtained by the actual measurement of the capacitance meter;
the position of the steel bar is detected, and the position, the capacitance value and the steel of the steel bar in the concrete can be judged according to the fluctuation condition of the capacitance valueThe relational expression of the rib diameter is: c ═ aB2+bB+c (1)；
Placing an electrode plate on the surface of the reinforced concrete, scanning the electrode plate along one side of the surface of the reinforced concrete to the other side at a constant speed, and measuring the water content of the reinforced concrete and the capacitance value of each position by taking 2.5mm as a step length;
the data acquisition and processing device obtains the corrected capacitance value of each position through the relational expression of the moisture content and the capacitance value, and the positional relation that the capacitance sensor can detect the steel bars is shown in fig. 6.
Detecting the thickness of the reinforcing steel bar protection layer, wherein the relational expression is as follows: c ═ eD2+fD+g (2)；
In the above 2 formulas, C is the corrected capacitance value, B is the diameter of the steel bar, D is the protective layer thickness of the steel bar, and a, B, C, e, f, and g are the values obtained after fitting;
detecting the diameter of a reinforcing bar
Placing an electrode plate on the surface of the reinforced concrete, scanning the electrode plate 11 along the reinforced concrete surface side with the same thickness and different diameters of the steel bar at a constant speed, correcting the maximum value of the capacitance and the water content measured each time, and comparing the relationship of the capacitance values of the same thickness of the steel bar protection layer under different diameters of the steel bar;
the relation between the diameter of the steel bar and the capacitance value is as follows: c ═ aB2+ bB + C, where C is the corrected capacitance value, B is the diameter of the steel bar, and a, B, and C are the values obtained after fitting, as shown in FIG. 7, it indicates that the capacitance sensor can detect the diameter relationship of the steel bar.
Detecting the relationship between the corrosion amount of the steel bar and the capacitance value
The electrode plate is scanned along the reinforced concrete surface with the same thickness and diameter of the steel bar protection layer along one side of the reinforced concrete surface at a constant speed, the capacitance and the moisture content measured each time are corrected, and the relationship between the corrosion amount of the steel bar and the capacitance is compared, as shown in fig. 8.
The relational expression of the capacitance value and the corrosion state of the steel bar is as follows: c ═ K0*△M (3)；
Wherein C is the corrected capacitance value,K0and △ M is the corrosion amount of the steel bars in the reinforced concrete to be detected, which is the coefficient in different reinforced concrete states.
Similar technical solutions can be derived from the solutions given in the figures and the description, as described above. However, any content of the technical solution not departing from the present invention still belongs to the right scope of the technical solution of the present application.
Claims (1)
1. The utility model provides a reinforcing bar detection device in concrete which characterized in that: comprises an electrode plate, a direct current power supply and a data acquisition and processing device;
the electrode plate comprises copper electrodes, polymethyl methacrylate and a water content testing device, wherein the two copper electrodes are placed at the same horizontal height and the same horizontal plane;
the data acquisition and processing device comprises a capacitance meter, wherein the angular frequency of the capacitance meter is set to be 10 KHz;
the display module is used for displaying a numerical value obtained after the capacitance sensor detects the numerical value;
the operation module is used for manually and practically inputting specific engineering information to set parameters;
the processing module is used for carrying out data analysis statistics on the value obtained by the capacitance meter and other related values;
and the data connecting wire socket is used for connecting the electrode plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922035488.2U CN210773884U (en) | 2019-11-22 | 2019-11-22 | Steel bar detection device in concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922035488.2U CN210773884U (en) | 2019-11-22 | 2019-11-22 | Steel bar detection device in concrete |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210773884U true CN210773884U (en) | 2020-06-16 |
Family
ID=71049284
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922035488.2U Active CN210773884U (en) | 2019-11-22 | 2019-11-22 | Steel bar detection device in concrete |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210773884U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110836631A (en) * | 2019-11-22 | 2020-02-25 | 青岛理工大学 | Device and method for detecting steel bars in concrete |
-
2019
- 2019-11-22 CN CN201922035488.2U patent/CN210773884U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110836631A (en) * | 2019-11-22 | 2020-02-25 | 青岛理工大学 | Device and method for detecting steel bars in concrete |
| WO2021098197A1 (en) * | 2019-11-22 | 2021-05-27 | 青岛理工大学 | Apparatus for testing rebar in concrete, and method therefor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110836631B (en) | Device and method for detecting steel bars in concrete | |
| CN107884631B (en) | Method and system for measuring power frequency electric field intensity | |
| CN112630270A (en) | Method for detecting state of reinforcing steel bar in concrete structure | |
| CN105258829A (en) | Underground engineering model test internal space stress measuring device and method | |
| CN104965231A (en) | Concrete water content detection device and method | |
| CN106596650A (en) | Graphene/cement composite material-based apparatus and method for detecting content of chloride ions in concrete | |
| CN205317923U (en) | Charge on --spot measurement calibration system of electric pile of filling of adapter of band signal sampling | |
| CN104964921A (en) | Steel bar corrosion degree detection system and detection method thereof | |
| CN204240955U (en) | Based on the measuring volume of tank device of 3 D laser scanning | |
| CN210773884U (en) | Steel bar detection device in concrete | |
| CN104634238A (en) | Method and device for measuring reinforcement protective layer thickness | |
| CN108151766A (en) | Localization method, magnetic nail positioning navigation error correcting method and the positioning device of magnetic nail | |
| CN103868632B (en) | A kind of contactless axis force of anchor measuring method based on eddy current impedance method | |
| CN104345216A (en) | Method and device for measuring specific resistance and 28-day strength of cement | |
| CN103323090A (en) | Electronic car weighing debugging novel method and device | |
| CN105021663A (en) | Salinity measurement method | |
| CN209559632U (en) | A kind of highway bridge bearing capacity detection device | |
| CN213579657U (en) | Calibrating and metering device for oiling machine | |
| CN107945533B (en) | Detection method for sensitivity and stability of geomagnetic vehicle detector | |
| GB2470225A (en) | Contactless microenvironment sensor | |
| CN205506168U (en) | Quiet appearance bimodulus charge level indicator | |
| CN204963772U (en) | Thickness tester | |
| CN106932160A (en) | Ancient building stress analysis method | |
| CN102901544B (en) | Material position and temperature sensor | |
| CN201876537U (en) | Detector for online arrester monitoring device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |